HBASE-26784 Addendum: Close scanner request should properly inherit original timeout and priority

hbase-client/src/main/java/org/apache/hadoop/hbase/client/ScannerCallable.java

@@ -312,13 +312,19 @@ private void close() {
       ScanRequest request =
           RequestConverter.buildScanRequest(this.scannerId, 0, true, this.scanMetrics != null);
       HBaseRpcController controller = rpcControllerFactory.newController();
-      // pull in the original priority, but then try to set to HIGH.
-      // it will take whatever is highest.
-      controller.setPriority(controller.getPriority());
-      controller.setPriority(HConstants.HIGH_QOS);
-      if (controller.hasCallTimeout()) {
-        controller.setCallTimeout(controller.getCallTimeout());
+
+      // Set fields from the original controller onto the close-specific controller
+      // We set the timeout and the priority -- we will overwrite the priority to HIGH
+      // below, but the controller will take whichever is highest.
+      if (getRpcController() instanceof HBaseRpcController) {
+        HBaseRpcController original = (HBaseRpcController) getRpcController();
+        controller.setPriority(original.getPriority());
+        if (original.hasCallTimeout()) {
+          controller.setCallTimeout(original.getCallTimeout());
+        }
       }
+      controller.setPriority(HConstants.HIGH_QOS);
+
       try {
         getStub().scan(controller, request);
       } catch (Exception e) {

hbase-client/src/main/java/org/apache/hadoop/hbase/ipc/HBaseRpcControllerImpl.java

@@ -262,4 +262,11 @@ public synchronized void notifyOnCancel(RpcCallback<Object> callback, Cancellati
       action.run(false);
     }
   }
+
+  @Override public String toString() {
+    return "HBaseRpcControllerImpl{" + "callTimeout=" + callTimeout + ", done=" + done
+      + ", cancelled=" + cancelled + ", cancellationCbs=" + cancellationCbs + ", exception="
+      + exception + ", regionInfo=" + regionInfo + ", priority=" + priority + ", cellScanner="
+      + cellScanner + '}';
+  }
 }

hbase-client/src/test/java/org/apache/hadoop/hbase/client/TestTableRpcPriority.java

@@ -32,14 +32,12 @@
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.times;
 import static org.mockito.Mockito.verify;
-
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Optional;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.atomic.AtomicInteger;
-
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hbase.Cell;
 import org.apache.hadoop.hbase.CellBuilderFactory;
@@ -74,6 +72,7 @@
  */
 @Category({ ClientTests.class, MediumTests.class })
 public class TestTableRpcPriority {
+
   @ClassRule
   public static final HBaseClassTestRule CLASS_RULE =
     HBaseClassTestRule.forClass(TestTableRpcPriority.class);
@@ -89,6 +88,7 @@ public void setUp() throws IOException, ServiceException {
     stub = mock(ClientProtos.ClientService.BlockingInterface.class);
 
     Configuration conf = HBaseConfiguration.create();
+
     ExecutorService executorService = Executors.newCachedThreadPool();
     conn = new ConnectionImplementation(conf, executorService,
       UserProvider.instantiate(conf).getCurrent(), new DoNothingConnectionRegistry(conf)) {
@@ -122,6 +122,16 @@ public void testScan() throws Exception {
     testForTable(TableName.valueOf(name.getMethodName()), Optional.of(19));
   }
 
+  /**
+   * This test verifies that our closeScanner request honors the original
+   * priority of the scan if it's greater than our expected HIGH_QOS for close calls.
+   */
+  @Test
+  public void testScanSuperHighPriority() throws Exception {
+    mockScan(1000);
+    testForTable(TableName.valueOf(name.getMethodName()), Optional.of(1000));
+  }
+
   @Test
   public void testScanNormalTable() throws Exception {
     mockScan(NORMAL_QOS);
@@ -153,11 +163,22 @@ private void testForTable(TableName tableName, Optional<Integer> priority) throw
     // just verify that the calls happened. verification of priority occurred in the mocking
     // open, next, then several renew lease
     verify(stub, atLeast(3)).scan(any(), any(ClientProtos.ScanRequest.class));
-    verify(stub, times(1)).scan(any(), assertScannerCloseRequest());
+    verify(stub, times(1)).scan(
+      assertControllerArgs(Math.max(priority.orElse(0), HIGH_QOS)), assertScannerCloseRequest());
   }
 
   private void mockScan(int scanPriority) throws ServiceException {
     int scannerId = 1;
+
+    doAnswer(new Answer<ClientProtos.ScanResponse>() {
+      @Override public ClientProtos.ScanResponse answer(InvocationOnMock invocation)
+        throws Throwable {
+        throw new IllegalArgumentException(
+          "Call not covered by explicit mock for arguments controller="
+          + invocation.getArgument(0) + ", request=" + invocation.getArgument(1));
+      }
+    }).when(stub).scan(any(), any());
+
     AtomicInteger scanNextCalled = new AtomicInteger(0);
     doAnswer(new Answer<ClientProtos.ScanResponse>() {
 
@@ -182,7 +203,7 @@ public ClientProtos.ScanResponse answer(InvocationOnMock invocation)
         return builder.setTtl(800).setMoreResultsInRegion(true).setMoreResults(true)
           .addResults(ProtobufUtil.toResult(result)).build();
       }
-    }).when(stub).scan(assertPriority(scanPriority), any(ClientProtos.ScanRequest.class));
+    }).when(stub).scan(assertControllerArgs(scanPriority), any());
 
     doAnswer(new Answer<ClientProtos.ScanResponse>() {
 
@@ -197,15 +218,19 @@ public ClientProtos.ScanResponse answer(InvocationOnMock invocation)
 
         return ClientProtos.ScanResponse.getDefaultInstance();
       }
-    }).when(stub).scan(assertPriority(HIGH_QOS), assertScannerCloseRequest());
+    }).when(stub).scan(assertControllerArgs(Math.max(scanPriority, HIGH_QOS)),
+      assertScannerCloseRequest());
   }
 
-  private HBaseRpcController assertPriority(int priority) {
+  private HBaseRpcController assertControllerArgs(int priority) {
     return argThat(new ArgumentMatcher<HBaseRpcController>() {
 
       @Override
       public boolean matches(HBaseRpcController controller) {
-        return controller.getPriority() == priority;
+        // check specified priority, but also check that it has a timeout
+        // this ensures that our conversion from the base controller to the close-specific
+        // controller honored the original arguments.
+        return controller.getPriority() == priority && controller.hasCallTimeout();
       }
     });
   }